1. Field of the Invention
The present invention relates to an improvement in a depth adjusting device for screwdrivers, and more particularly to such a depth adjusting device for setting self drilling fasteners, self tapping fasteners, drywall fasteners and the like at a specific distance relative to a given work surface of relatively soft board such as gypsum board and asbestos board.
2. Description of the Prior Art
Such a depth adjusting device is disclosed, for example, in U.S. Pat. Nos. 3,527,273 and 3,712, 352. The disclosed device includes a locking collar threaded onto the forward end of the tool housing, a locator sleeve carried by the locking collar, and a compression spring acting between the locking collar and the locator sleeve to axially move the locator sleeve. When adjusting the axial position of the locator sleeve, the operator must rotate the locking collar against the biasing action of the compression spring, to also rotate the locator sleeve in order to vary the distance between the work contacting end of the locator sleeve and the end of a screwdriver bit tip. This rotating operation of the locator sleeve tends to require a due force and time. Especially, when a substantial depth adjustment is made or when the bit is removed for exchange, the rotating operation of the locking collar and the locator sleeve is cumbersome, and the assembling procedure of the device is troublesome. Further, the disclosed device has an increased number of components and is complicated in construction.